Centrifugal pulp screen



G. F. SHEVLIN CENTRIFUGAL PULP SCREEN April 3, 1928. 6 1,664,996

Filed March 51. 1927 2 Sheets-Sheet 1 TW Ill I W III! 25/ IP52? l Eum!Win25 INVENTOR Patented Apr. 3, 1928.

UNITED STATES ATENT OFFICE.

GEORGE E. snnvnrn, or e-Lnns FALLS, new YORK, ASSIGNOR To GEORGE E.sHEvLIN & son, or GLnns FALLS, NEW YORK, A PARTNERSHIP GOMPOSEID orGEORGE I. SHEVLIN, SR, AND GEORGE E. SHEVLIN, JR.

CENTRIFUGAL PULP SCREEN.

Application filed March 31, 1927.

The present invention relates to an improvement in centrifugal pulpscreens and more particularly to the stock distributor or runner elementthereof. The invention furthermore is an improvement on the centrifugalpulp screen stock distributor as shown an described in U. S. LettersPatent No. 1,436,411, granted to me, November 21, 1922. The primaryobject of the invention in this case as in the construction shown anddescribed in the Letters Patent aforesaid is to obtain an evendistribution of the stock in forcing or directing the same against thescreen. The apparatus as shown in the patent includes a centrallydisposed hub, a cylindrical member arranged concentrically with the huband connected therewith by a series of spaced preferably radially placedblades which extend beyond the cylindrical member, together with aseries of vanes, there being a vane associated with that portion of eachblade which extends beyond the cylindrical member and in the cylindricalmember there are sets of ports or openings making passageways throughthe same adj acent the inner ends of the vanes, which vanes extend fromthe top or upper end of the distributor to a point approximately midwaythereof.

It has been found in the use of a stock distributor or runner of thistype that in some instances it operates satisfactorily. In otherinstances, however, particularly with pulp stock of certainconsistencies, the stock or a large portion thereof in passing throughthe apertures in the cylindrical member is projected directly againstthe screen without the intervention of the vane. In such instances, ofcourse, the stock is not projected with the force with which it wouldhave been pro j ected through the action of centrifugal force whencaused to pass along the surface of the vanes. Consequently, in carryingout the present invention and in order to make the apparatus fullyeffective with pulp stock of substantially all consistencies, I employ aplurality of deflector plates each associated with one of the vanes sothat as the stock passes through the port in the cylindrical member thedeflector plate directs the same positively to the corresponding vane,thereby obviating all possibility of any of the stock being projecteddirectly from the port or aperture in the cylindrical member Serial No.179,773.

through which it passes to the screen, and thereby utilizing the vanesto their fullest capaclty 1n imparting swift motion to the stock as thesame is delivered therefrom against the screen of the apparatus.

In carrying out the present invention I employ suitable means foradjusting or regulating the passage of the stock from the centralcompartments to the exterior thereof so that depending upon theconsistency of the stock and the speed of the apparatus, an evendistribution of thestock and a maximum ehiciency of the apparatus may beattamed.

The invention will be hereinafter more particularly described inconjunction with the accompanying drawings in which 1*1gure 1 is asectional plan on line 1-1, Fig.

Fig. 2 is an elevation of a stock distributor or runner for acentrifugal screen asmade in accordance with this invention. Fig. 3 is asectional elevation on line 33, Fig. 1, and i Fig. 4 is a perspectiveView on an enlarged scale illustrating one of the deflector plates.

Referring to the drawing it will be seen that in carrying out theinvention the stock dlstributor or runner made in accordance therewithis so constructed as to include a hub 10 adapted to be mounted on andconnected to a suitable shaft by which it may be turned rapidly. The hub10 is connected to a cylindrical member 11 by means of a series ofblades 12 which are preferably placed in radial positions and divide thespace between the hub and the cylindrical member into a correspondingnumber of compartments orspaces13. Each blade 12 extends appreciablybeyond the cylindrical member as indlcated at 14. The top of thedistributor is preferably flat as indicated at 15, and

the bottom is preferably made concavo-convex as'indicated at 16. Theblades 12 and their extensions 14 preferably extend from the top to thebottom of the runner.

I also employ a plurality of vanes indicated at 17. There is a vaneassociated with each of the extended portions 14 of the ribs and anadjacent portion of the cylindrical member 11. These vanes 17 extendfrom the top or upper portion of the distributor to a pointapproximately centrally thereof, that is midway of its height. In thewall of the cylindrical member between each of the extensions 14 of theblades, I provide a port indicated at 18. This port is preferably anelongated rectangular slot and is adaptedto be covered to a greater orlesser extent by a door 19 so as to determine the area of the port andconsequently the amount of: stock Vwhich under given conditions may passand substantially coextensive therewith and longitudinally of thedistributor. As illustrated; in the drawing, the deflector plates aredesignated at 22 and as shown in Fig.

4, the body of the plate is curx' ed and at one end formed with a'flange 23 adapted to fit 1n a recess or to extend through the upperportion of the corresponding blade extension 14 and to be connected tothe top wall of the distributor by means of a rivet or screw 24. At theinner or lower end each deflector plate is formedwith a bracket 25, aportion of which is adapted to bear against the adjacent surface of thecorresponding blade extension 1 1 and to be connected thereto by meansof bolts. 26 or otherwise so as to secure the deflector plate inpositionin the apparatus.

Below the vanes 17' and the associated defiector plates the cylindricalmember 11 is provided in suitably spaced positionswith a plurality ofholes 27 an'dalso with spaced slots 28. It will furthermore be notedthat there is an appreciable space between the lower or inner end of thecylindrical member and the'upper face of the concavo-convex bottom plate16, which space is indicated at 29.

In the use of this apparatus the stock is supplied through any suitablemeans to the compartments 13 between the hub 10 and the cylindricalmember 11. From these. com partments as indicated by the arrows, thestoclcpasses through the ports 18 and di rectly against the deflectorplates 22 by means of which the stock is directed positively to thecorresponding-vanes'so that none of the stock can be projected directlythrough the opening or port in the cylindrical member tothe screen.Consequently the action of centrifugal force due to the rapid rotationof the distributor or runner imparts a rapid fiowto the stock causingthe same as it leavesthe runner to be projected with considerable forceagainst the screen. This action as will be understood, applies to thelighter portion of the stock as the apparatus utilized for this purposeis in the upper portion of the distributor. 'Ihe heavier portion of thestock passes in a customary manner toward the bottom of the compartmentsin the cylindrical member and passes through the openingsor ports 27 and28 therein and project-ed against the screen by the extensions 14 of theblades. Furthermore, that portion of the stock which is not delivered ineither of the manners to whicl'i reference has been. made, is permittedto pass by way of the space 29 to the upper surface of the bottomot thedistributor and thence to the pipe lines or other means through whichthe sliversmay be discharged.

I claim as my invention: f

1. In a centri'higalpulp screen, a stock. distributor comprising a hub,a cylindrical member, blades extending from the hub toaud beyondthe-cylindrical member, a plurality of vanes each associated with theouter portion of the cylindrical member and an adjacent portion of oneof the blades, and

a plurality of deflect-or plates each associated with awvane and soconstructed and secured in position as to positively direct the passageof stock to the corresponding vane. v

2; Ina centrifugal pulp screen, a stockdistributor comprising a hub,acylindricai" member, a plurality ofblades extending there being a portthrough the wall of the- V cylindrical member between each of the partsof the blades extending beyond the same, means for controlling thedischarge 0& stock through the said ports, and a plurality of deflectorplates each associated with one of the said vanes and adapted to directthe flow of the stool: as the same passes through one of the said portsto the corresponding vane. a. s

3. In a centrifugal pulp screen, a stock distributor comprising a hub, acylindrical' member, a plurality of blades extending from the hub toand. beyond the" said cylindrical member, the cylindrical member havinga series of portstherein, each port being placed adjacent one of'theextended portions of a blade, a corresponding numberof doors eachcontrolling a port, means for adjusting the position of each door todetermine the area. of the corresponding port, a pluralityo'fivaneseachassociated with an outer portion of one of the blades and.the adjacent portion of the cylindricalmemben, and a plurality ofdeflector plates each adapted to direct the flow of stock ass-the samepasses through the corresponding port to the corresponding vane.

1. In a ccntrifiugal pulp screen, a stock distributor comprising a hub,a cylindrical member concentric.therewith, a plurality oi? bladesextending from the hub to" and be yond the said cylindrical member,there being a plurality of ports in the wall of the cylindrical member,each port being adjacent a blade, a plurality of doors each associatedwith one of the ports, means for adjusting each door to position todetermine the area of the corresponding port, a plurality of vanes eachextending from the top of the distributor to a point approximatelymidway of its length and associated With the outer portion of a bladeand the adjacent portion of the Wall of the cylindrical member, the saidports and doors being also sub stantially coextensive of the extent ofthe said vanes, and a plurality of deflector plates each associated witha corresponding vane and adapted to direct the flow of the stock as thesame passes through the corresponding port to the corresponding vane.

5. In a centrifugal pulp screen, a stock distributor comprising a hub, acylindrical member concentric therewith, a plurality of blades extendingfrom the hub to and beyond the said cylindrical member, there ity ofvanes each extending from the top of the distributor to a pointapproximately midway of its length and associated With the outer portionof a blade and the adjacent portion of the wall of the cylindricalmember, the said ports and doors being also substantially coextensive ofthe extent of the said vanes, and a plurality of deflector plates, eachdeflector plate being curved and secured in position to the outerportion of one of the said blades so as to extend over a correspondingport with Which it is sub- 1927 GEO. F. SHEVLIN.

